Your gun is a K22 Target Masterpiece by Smith & Wesson. There were several options eg. wide hammer, wide trigger. They also made a K38 (which I shoot in a Bullseye Target league). They are very collectable. Did it come with the original factory box?
If it has a round butt, it is what I described, square butt is a Combat Masterpiece.
The round butt are divided into 3 configurations: K22 Outdoorsman, ser# in the 600,000 range mfg 1931-1940; Pre-War K22, ser# range 682,420-696,952; Post-War K22, ser# all started with the letter K , 1946-1957.
Values range from: Outdoorsman: $200 to $2000; Pre-War:$350 to $4650.00; Post_war: $150 to $775. Totally dependent upon condition of gun.
Take care of it as it is a shooter and definately a classic.
Cowboy, according to your info I have a prewar combat masterpiece, square butt, 6 " bbl. Thanks again.